Vulnerability-Lookup

GHSA-HPXM-6496-49XP

Vulnerability from github – Published: 2026-10-18 18:32 – Updated: 2026-10-18 18:32

Details

In the Linux kernel, the following vulnerability has been resolved:

nvmet: copy the hostid into the ctrl before creating PR pc_refs

Commit 6202783184bf ("nvmet: Improve nvmet_alloc_ctrl() interface and implementation") added a second uuid_copy() of args->hostid near the end of nvmet_alloc_ctrl(), and commit 7b658153f1b8 ("nvmet: Remove duplicate uuid_copy") removed the original copy that sat before nvmet_ctrl_init_pr() instead of the new one.

Since then nvmet_ctrl_init_pr() snapshots ctrl->hostid into the per-controller per-namespace reservation refs while the uuid_copy() from the connect data runs later, after the controller is published. The ctrl is allocated with kzalloc(), so every pc_ref created on this path stores the nil UUID.

pc_ref->hostid has a single consumer: nvmet_pr_set_ctrl_to_abort() matches it against the preempted registrant's hostid to kill and drain the victim's in-flight I/O for Preempt and Abort. The match can never hit with the nil UUID, so whenever a namespace with reservations enabled exists before a host connects, which includes every reconnect, Preempt and Abort silently degrades into a plain Preempt: the preempting host sees success while the victim's in-flight I/O is still in the air.

Copy the hostid where the rest of the connect data is consumed, before the controller is published and before nvmet_ctrl_init_pr() takes its snapshot.

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-98723"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-18T16:17:25Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnvmet: copy the hostid into the ctrl before creating PR pc_refs\n\nCommit 6202783184bf (\"nvmet: Improve nvmet_alloc_ctrl() interface and\nimplementation\") added a second uuid_copy() of args-\u003ehostid near the end\nof nvmet_alloc_ctrl(), and commit 7b658153f1b8 (\"nvmet: Remove duplicate\nuuid_copy\") removed the original copy that sat before\nnvmet_ctrl_init_pr() instead of the new one.\n\nSince then nvmet_ctrl_init_pr() snapshots ctrl-\u003ehostid into the\nper-controller per-namespace reservation refs while the uuid_copy()\nfrom the connect data runs later, after the controller is published.\nThe ctrl is allocated with kzalloc(), so every pc_ref created on this\npath stores the nil UUID.\n\npc_ref-\u003ehostid has a single consumer: nvmet_pr_set_ctrl_to_abort()\nmatches it against the preempted registrant\u0027s hostid to kill and drain\nthe victim\u0027s in-flight I/O for Preempt and Abort.  The match can never\nhit with the nil UUID, so whenever a namespace with reservations\nenabled exists before a host connects, which includes every reconnect,\nPreempt and Abort silently degrades into a plain Preempt: the\npreempting host sees success while the victim\u0027s in-flight I/O is still\nin the air.\n\nCopy the hostid where the rest of the connect data is consumed, before\nthe controller is published and before nvmet_ctrl_init_pr() takes its\nsnapshot.",
  "id": "GHSA-hpxm-6496-49xp",
  "modified": "2026-10-18T18:32:01Z",
  "published": "2026-10-18T18:32:01Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98723"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/23194531595c5d1d4454e3a607b0c8fc0c4e8695"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5211fed41d7ec90e9ab7239dc4bffffe4d0b2b62"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d3d6d7efdacc08616d23b3ac42272a494951dc0f"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-98723 (GCVE-0-2026-98723)

Vulnerability from cvelistv5 – Published: 2026-10-18 15:46 – Updated: 2026-10-19 09:24

Title

nvmet: copy the hostid into the ctrl before creating PR pc_refs

Summary

In the Linux kernel, the following vulnerability has been resolved: nvmet: copy the hostid into the ctrl before creating PR pc_refs Commit 6202783184bf ("nvmet: Improve nvmet_alloc_ctrl() interface and implementation") added a second uuid_copy() of args->hostid near the end of nvmet_alloc_ctrl(), and commit 7b658153f1b8 ("nvmet: Remove duplicate uuid_copy") removed the original copy that sat before nvmet_ctrl_init_pr() instead of the new one. Since then nvmet_ctrl_init_pr() snapshots ctrl->hostid into the per-controller per-namespace reservation refs while the uuid_copy() from the connect data runs later, after the controller is published. The ctrl is allocated with kzalloc(), so every pc_ref created on this path stores the nil UUID. pc_ref->hostid has a single consumer: nvmet_pr_set_ctrl_to_abort() matches it against the preempted registrant's hostid to kill and drain the victim's in-flight I/O for Preempt and Abort. The match can never hit with the nil UUID, so whenever a namespace with reservations enabled exists before a host connects, which includes every reconnect, Preempt and Abort silently degrades into a plain Preempt: the preempting host sees success while the victim's in-flight I/O is still in the air. Copy the hostid where the rest of the connect data is consumed, before the controller is published and before nvmet_ctrl_init_pr() takes its snapshot.

Severity

No CVSS data available.

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 6820 records in the last 180 days details

References

3 references

URL	Tags
https://git.kernel.org/stable/c/d3d6d7efdacc08616…
https://git.kernel.org/stable/c/23194531595c5d1d4…
https://git.kernel.org/stable/c/5211fed41d7ec90e9…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 7b658153f1b8a79ed98980f2fef7b92a66aeb9cd , < d3d6d7efdacc08616d23b3ac42272a494951dc0f (git) Affected: 7b658153f1b8a79ed98980f2fef7b92a66aeb9cd , < 23194531595c5d1d4454e3a607b0c8fc0c4e8695 (git) Affected: 7b658153f1b8a79ed98980f2fef7b92a66aeb9cd , < 5211fed41d7ec90e9ab7239dc4bffffe4d0b2b62 (git)
Linux	Linux	Affected: 6.15 Unaffected: 0 , < 6.15 (semver) Unaffected: 6.18.56 , ≤ 6.18.* (semver) Unaffected: 7.2.10 , ≤ 7.2.* (semver) Unaffected: 7.3 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/nvme/target/core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "d3d6d7efdacc08616d23b3ac42272a494951dc0f",
              "status": "affected",
              "version": "7b658153f1b8a79ed98980f2fef7b92a66aeb9cd",
              "versionType": "git"
            },
            {
              "lessThan": "23194531595c5d1d4454e3a607b0c8fc0c4e8695",
              "status": "affected",
              "version": "7b658153f1b8a79ed98980f2fef7b92a66aeb9cd",
              "versionType": "git"
            },
            {
              "lessThan": "5211fed41d7ec90e9ab7239dc4bffffe4d0b2b62",
              "status": "affected",
              "version": "7b658153f1b8a79ed98980f2fef7b92a66aeb9cd",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/nvme/target/core.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.15"
            },
            {
              "lessThan": "6.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.56",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.56",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.10",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnvmet: copy the hostid into the ctrl before creating PR pc_refs\n\nCommit 6202783184bf (\"nvmet: Improve nvmet_alloc_ctrl() interface and\nimplementation\") added a second uuid_copy() of args-\u003ehostid near the end\nof nvmet_alloc_ctrl(), and commit 7b658153f1b8 (\"nvmet: Remove duplicate\nuuid_copy\") removed the original copy that sat before\nnvmet_ctrl_init_pr() instead of the new one.\n\nSince then nvmet_ctrl_init_pr() snapshots ctrl-\u003ehostid into the\nper-controller per-namespace reservation refs while the uuid_copy()\nfrom the connect data runs later, after the controller is published.\nThe ctrl is allocated with kzalloc(), so every pc_ref created on this\npath stores the nil UUID.\n\npc_ref-\u003ehostid has a single consumer: nvmet_pr_set_ctrl_to_abort()\nmatches it against the preempted registrant\u0027s hostid to kill and drain\nthe victim\u0027s in-flight I/O for Preempt and Abort.  The match can never\nhit with the nil UUID, so whenever a namespace with reservations\nenabled exists before a host connects, which includes every reconnect,\nPreempt and Abort silently degrades into a plain Preempt: the\npreempting host sees success while the victim\u0027s in-flight I/O is still\nin the air.\n\nCopy the hostid where the rest of the connect data is consumed, before\nthe controller is published and before nvmet_ctrl_init_pr() takes its\nsnapshot."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T09:24:33.989Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/d3d6d7efdacc08616d23b3ac42272a494951dc0f"
        },
        {
          "url": "https://git.kernel.org/stable/c/23194531595c5d1d4454e3a607b0c8fc0c4e8695"
        },
        {
          "url": "https://git.kernel.org/stable/c/5211fed41d7ec90e9ab7239dc4bffffe4d0b2b62"
        }
      ],
      "title": "nvmet: copy the hostid into the ctrl before creating PR pc_refs",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98723",
    "datePublished": "2026-10-18T15:46:59.444Z",
    "dateReserved": "2026-09-25T10:25:14.366Z",
    "dateUpdated": "2026-10-19T09:24:33.989Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

Order JSON

Publication & reservation Sightings KEV catalogs Other timestamps

Loading timeline…

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted